The emergence of Lyme disease (LD) as a public health problem in Connecticut over the last 28 years is due to the increased risk of tick bites among persons who live increasingly in suburban and rural areas near woodlands in Connecticut. In 2002, Connecticut had the highest reported rate of LD of any state (136 cases per 100,000 population). This proposal will build upon the existing Connecticut Lyme Disease Program, a multi-agency collaborative effort in its 12th year. This collaborative effort involves the Department of Public Health (DPH), the Connecticut Agricultural Experiment Station (CAES), the Connecticut Emerging Infections Program at the Yale University School of Public Health, the Westport-Weston Health District, the Ledge Light Health District, and the Torrington Area Health District. The goal of the program's activities is to reduce the incidence of Lyme disease and other tick-borne diseases in including babesiosis and ehrlichiosis. This proposal will evaluate the effectiveness of the currently available measures to reduce the risk of LD in the United States. The community-based intervention projects in the three health districts, which are funded under current cooperative agreements with CDC, will be continued. These projects will continue to promote integrated strategies to reduce tick abundance, promote protective measures, and implement landscape modifications, including methods under development to reduce tick abundance by treating white-footed mice with acaricide in bait-boxes and deer with a 4-poster topical treatment system, and application of entomopathogenic fungus. Evaluation of the effectiveness of the diverse prevention measures and the costs of these interventions in relation to the number of cases prevented will include several methods including monitoring surveillance data, effect on vector populations, surveys of residents, pesticide applicators, and physicians, an analytic epidemiological study, and a case study of persons with confirmed exposure.